Don’t do this.
Thermite will weld everything together. Use detonating cord instead.
That is way overkill also. Take a chainsaw and cut the whole door frame out of the wall. Then you lay it down on a table to work on it.
Jamb, thank you! I knew that looked wrong!
I’ll try to get some pictures tonight
I got it!
Couldn’t sleep last night, so fixed the door at about 3:30am today.
Baracus and JBDiv were right. The hollow tunnel through which the actual bolt slides was what I was tugging at. :smack:
It wasn’t wasted effort though, as it had to be opened up in order for me to get to the actual bolt; it took quite a bit of prying but I managed to open up enough of a hole to get in there. Then there was no way to grab on to the bolt. I tried chewing gum and a pencil, but the angle was wrong. Then I tried a rare earth magnet but it wouldn’t fit inside, and wasn’t strong enough to pull it from the bore hole.
Buckycubes to the rescue! ! ! I raided the Celtling’s toy box and made a bucket brigade of buckycubes. These were strong enough to grab onto each other, small enough to fit into the hole, and able to pull it out enough to open the door.*
Whoo hoooo! It took all my strength not to wake the neighborhood with a Rebel Yell!
Then the damage I had done prying it open become the problem. “Flare” does not begin to describe what that thing looked like at this point, but it had to be squished back together in order to pull it from the door through the bolt hole.
Once that was done it was five minutes to install the new knob and in five more I was sleeping soundly.
Thanks again to everybody - especially the Doper who volunteered by PM to walk me through it by telephone. Your kindness is greatly appreciated! 
- I should note here how seriously PO’ed I was when I ordered these on-line and then realized how insanely small they are when the box finally arrived. That’ll learn me!
Hip-hip-hooray!
Glad to hear, that you ‘got-er-done’! 